USPTO Patents Application 10086742

U.S. Serial No. 10/086,742
Attorney Docket 614.1747CD2C

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IN THE CLAIMS

Please AMEND the claims as indicated below:

1 . (ORIGINAL) An optical transmission system comprising:

an optical transmitter transmitting a WDM optical signal including a plurality of optical
signals with different wavelengths;

means for amplifying the WDM optical signal received from the optical transmitter with
substantially equal gain with respect to the wavelengths of the plurality of the optical signals and
for outputting the amplified WDM optical signal; and

an optical receiver receiving the amplified WDM optical signal output from said means,
said means including

a first-stage optical amplifier which amplifies the received WDM optical signal,
a level controller which controls a power level of the WDM optical signal amplified
by the first-stage optical amplifier, and

a second-stage optical amplifier which amplifies the WDM optical signal of which
level is controlled by the level controller.

2. (ORIGINAL) An optical transmission system comprising:

a first optical transmission line through which a WDM optical signal including a plurality of
optical signals with different wavelengths is transmitted;

an optical amplifier with a configuration to amplify the WDM optical signal with substantially
equal gain over the wavelengths of the optical signals; and

a second optical transmission line through which the amplified WDM optical signal is
transmitted, wherein the configuration of the optical amplifier includes

a front-stage optical amplifier which amplifies the WDM optical signal to produce a
front-stage amplified WDM optical signal,

a level controller which controls a power level of the front-stage amplified WDM
optical signal and outputs a controlled WDM optical signal, and

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U.S. Serial No. 10/086,742
Attorney Docket 614.1747CD2C

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a rear-stage optical amplifier which amplifies the controlled WDM optical signal to
produce a rear-stage amplified WDM optical signal.

3. (ORIGINAL) An optical transmission system comprising:

an optical transmitter transmitting a WDM optical signal including a plurality of optical
signals with different wavelengths;

an optical amplifier with a configuration to amplify the WDM optical signal from the optical
transmitter with substantially equal gain over the wavelengths of the optical signals; and

an optical receiver receiving the amplified WDM optical signal from the optical amplifier,
wherein the configuration of the optical amplifier includes

a first-stage optical amplifier which amplifies the WDM optical signal,
a level controller which controls a power level of the WDM optical signal amplified
by the first-stage optical amplifier, and

a second-stage optical amplifier which amplifies the WDM optical signal of which
level is controlled by the level controller.

4. (ORIGINAL) An optical transmission system comprising:

an optical transmitter transmitting a WDM optical signal including a plurality of optical
signals with different wavelengths through a first optical transmission line;

means for amplifying the WDM optical signal received from the first optical transmission
line with substantially equal gain with respect to the wavelengths of the plurality of the optical
signals and for outputting the amplified WDM optical signal, the means including

a first-stage optical amplifier which amplifies the received WDM optical signal,
a level controller which controls a power level of the WDM optical signal amplified
by the first-stage optical amplifier, and

a second-stage optical amplifier which amplifies the WDM optical signal of which
level is controlled by the level controller; and

an optical receiver receiving the amplified WDM optical signal through a second optical
transmission line through.

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U.S. Serial No. 10/086,742
Attorney Docket 614.1747CD2C

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5. (CANCELED)

6. (CANCELED)

7. (CANCELED)

8. (NEW) An optical transmission system according to claim 1 , wherein the level
controller includes a variable optical attenuator which variably attenuates the WDM optical signal
amplified by the first-stage optical amplifier and thereby controls the power level of the WDM
optical signal amplified by the first-stage optical amplifier.

9. (NEW) An optical transmission system according to claim 2, wherein the level
controller includes a variable optical attenuator which variably attenuates the front-stage amplified
WDM optical signal and thereby controls the power level of the front-stage amplified WDM optical
signal.

10. (NEW) An optical transmission system according to claim 3, wherein the level
controller includes a variable optical attenuator which variably attenuates the WDM optical signal
amplified by the first-stage optical amplifier and thereby controls the power level of the WDM
optical signal amplified by the first-stage optical amplifier.

1 1 . (NEW) An optical transmission system according to claim 4, wherein the level
controller includes a variable optical attenuator which variably attenuates the WDM optical signal
amplified by the first-stage optical amplifier and thereby controls the power level of the WDM
{_ optical signal amplified by the first-stage optical amplifier.

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